Google Instant and the Long Tail
Just something I thought worth pointing out. Since users will now be able to see results before they finish typing their query, it is very possible that sites that rank better for the short tail will get more traffic.
If someone is, for example, searching for baseball card dealers, and a baseball card dealer ranks in the top 3 for baseball card, the user will probably not wait to finish their complete query.
Better start focusing on root keywords.